Tire cord



Patented Sept. 23, 1941 TIRE 001m Camille Dreyfus, New York, NY.

N Drawing. Application June 15, 1939, Serial No. 279,259

zation, to which they are exposed during treat- Claims.

This invention relates to the treatment of textile yarns, filaments andthe like made of cellulosic materials, particularly those made of orcontaining regenerated cellulose, partially saponified cellulose esters,or cotton, in order to improve their properties.

An object of this invention is the treatment of cellulosic yarns orfilaments in order to improve their wearing qualities.

Another object of this invention is the treatment of yarns or filamentsmade of or containing cellulosic material so as to render them moresuitable for use in the manufacture of tire cords.

A further object of this invention is to maintain as much as possiblethe strength of yarns or filaments made of or containing cellulosicmaterial during the manufacture of tire cords. Other objects of theinvention will appear from the following detailed description.

In the manufacture of tires and other operations wherein yarns areexposed to relatively high temperatures and/or atmospheres of relativelylow humidity, yarns of cellulosic material tend to lose part of theirstrength particularly when subjected to torsional stresses. I have foundthat this is partly dueto the loss by the yarns of natural moistureunder such conditions.

I have found that if yarns made of cellulosic materials are treated withhygroscopic liquid that has no deleterious efiect on the yarns, becausethe yarns are protected against the lossof all moisture, the yarns donot suffer appreciable loss of strength when exposed to relatively hightemperatures and/or relatively dry atmosphere. As a result, cordformation is facilitated and the resulting tires have increased strengthand wearing properties.

While this invention is of value in connection with the treatment ofyarns, threads or cords made of filaments of fibers of cellulosicmaterial, such as partially or completely saponified cellulose acetateor other cellulose esters, or other regenerated cellulose such as fromviscose or cuprammonium solutions of cellulose, cotton, flax, etc.,particularly good results are obtained in connection with the treatmentof yarn of high tenacity obtained by the saponification of cellu-v loseacetateor other cellulose ester yarn that has been stretched beforesaponiflcation, while softened, up to 200 to 500%.

The celluloslc yarn may be treated with any relatively non-volatilehygroscopic liquid, provided it has no deleterious effect either atordinary temperatures or the higher temperatures, such as 125 to 150 C.prevailing during vulcaniment or use. Generally as hygroscopic materialwe prefer to employ relatively non-volatile polyhydric alcohols or theirpartial ethers or esters,

such as glycerol, ethylene glycol, propylene glycol,

diethylene glycol, the monoethyl ether of diethylene glycol, monoacetin(glyceryl monoacetate).

In order to stabilize the solution in which the hygroscopic liquid isapplied against change of volume, viscosity or concentration due toevaporation or absorption of water, it is preferable to add a quantityof water substantially equal to the amount of water these liquids tendto absorb from the air, the amount of water being 30% in the case ofdiethylene glycol, 13% in the case of ethylene glycol and 33% in thecase of glycerol.

If desired, the hygroscopic material may be applied in conjunction orseparately with other materials such as lubricants containing tricresylphosphate, sulfonated vegetable oils, and/or soaps.

The hygroscopic material may be applied to the yarns before, during orafter any textile operation to which they are subjected. Thus it may beapplied to the yarns or filaments during any winding or twistingoperation by passing the same in contact with a wick, roller, disc orother furnishing device that dips into the liquid comprising thehygroscopic material. The yarns or filaments may be drawn through asolution or emulsion of the hygroscopic material or the same may besprayed upon the yarn. The hygroscopic material may also be applied tothe yarns or Illaments in hank form by hand dipping methods, or theyarns may be treated with the hygroscopic material by padding orspraying after they have been formed into a cord.

The amount of hygroscopic material applied will'vary with the type ofyarn and especially with the type of cord into which it is to beconverted. Thlls heavy duty cords such as are used in the manufacture oftruck tires will require a higher proportion of hygroscopic materialthan will cords which are to be used in a tire for a passengerautomobile. We have found that excellent results are obtained where 1 to10.0% of hygroscopic material on the weight of the yarn is applied toand/or retained by the yarn.

The following is an example of an application of the invention, it beingunderstood that thisis given by way of illustration only.

Example,

Travelling yarns of regenerated cellulose of about 270 denier obtainedby the saponification formly and even1y.impregnated with 'for cords intire manufacture.

been stretched 200% before saponiflcation, having a twist of about 5turns per inch, are contacted with a wick which dips into a bathconsisting of 75% of glycerine and 25% of water. The wick is adjusted sothat-5% of the glycerine, on the basis of the weight of the yarn, isretained by the travelling yarn. The yarn is thus unithe glycerine.-

Yarns thus treated are plyed by twisting four ends together 14 turns perinch, left. Three plys thus formed are then twisted about 12 turns perinch, right, in order to obtain a cable suitable The travelling yarnafter it receives the lubricant may pass directly to the plying andcabling machines.

The treated yarns when incorporated in a tire maintains markedlyimproved strength as compared with similar yams untreated.

It is to be understood that the foregoing detailed description is merelygiven by way of illustration and that many variations maybe made thereinwithout departing from the spirit of my invention.

Having described my invention, what I desire to secure by Letters Patentis:

-1. Tire cords of improved strength comprising cellulosic yarns having ahygroscopic liquid incorporated therein.

2. Tire cords of improved strength comprising group consisting ofpolyhydric alcohols, their' partial ethers and partial esters.

4. Tire cords of improved strength comprising regenerated celluloseyarns obtained by the saponiflcat'on of highly stretched celluloseacetate yarns, said regenerated cellulose yarns having incorporatedtherein a hygroscopic liquid selected from the group consisting ofpolyhydric alcohols, their partial ethers and partial esters.

5. Tire cords of improved strength comprising regenerated celluloseyarns obtained by the saponiflcation of highly stretched celluloseacetate yarns, said regenerated cellulose yarns having glycerineincorporated therein.

emu: names.

